* {
    padding: 0;
    margin: 0;
  }
  .box {
    height: 500px;
    width: 400px;
    margin: 200px auto;
  }
  .box h1 {
    text-align: center;
  }
  .box > div input {
    width: 400px;
    height: 50px;
    margin-top: 40px;
  }
  .box > div button {
    margin-top: 40px;
    width: 400px;
    height: 50px;
    background-color: skyblue;
    border: none;
  }
  .ts {
    display: none;
  }
  .mmts {
    display: none;
  }
  .active {
    display: block;
    color: red;
  }